Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933177AbbFVIqO (ORCPT ); Mon, 22 Jun 2015 04:46:14 -0400 Received: from mail-wi0-f170.google.com ([209.85.212.170]:34632 "EHLO mail-wi0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933199AbbFVIqF (ORCPT ); Mon, 22 Jun 2015 04:46:05 -0400 Date: Mon, 22 Jun 2015 10:46:01 +0200 From: Michal Hocko To: Pali =?iso-8859-1?Q?Roh=E1r?= Cc: Darren Hart , Matthew Garrett , platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 3/4] dell-laptop: Fix allocating & freeing SMI buffer page Message-ID: <20150622084601.GE4430@dhcp22.suse.cz> References: <1434875967-13370-1-git-send-email-pali.rohar@gmail.com> <1434876063-13460-1-git-send-email-pali.rohar@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1434876063-13460-1-git-send-email-pali.rohar@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2025 Lines: 65 On Sun 21-06-15 10:41:03, Pali Roh?r wrote: > This commit fix kernel crash when probing for rfkill devices in dell-laptop > driver failed. Function free_page() was incorrectly used on struct page * > instead of virtual address of SMI buffer. > > This commit also simplify allocating page for SMI buffer by using > __get_free_page() function instead of sequential call of functions > alloc_page() and page_address(). > > Signed-off-by: Pali Roh?r Looks good to me. FWIW Acked-by: Michal Hocko > --- > drivers/platform/x86/dell-laptop.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c > index aaef335..0a91599 100644 > --- a/drivers/platform/x86/dell-laptop.c > +++ b/drivers/platform/x86/dell-laptop.c > @@ -306,7 +306,6 @@ static const struct dmi_system_id dell_quirks[] __initconst = { > }; > > static struct calling_interface_buffer *buffer; > -static struct page *bufferpage; > static DEFINE_MUTEX(buffer_mutex); > > static int hwswitch_state; > @@ -2097,12 +2096,11 @@ static int __init dell_init(void) > * Allocate buffer below 4GB for SMI data--only 32-bit physical addr > * is passed to SMI handler. > */ > - bufferpage = alloc_page(GFP_KERNEL | GFP_DMA32); > - if (!bufferpage) { > + buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32); > + if (!buffer) { > ret = -ENOMEM; > goto fail_buffer; > } > - buffer = page_address(bufferpage); > > ret = dell_setup_rfkill(); > > @@ -2165,7 +2163,7 @@ static int __init dell_init(void) > fail_backlight: > dell_cleanup_rfkill(); > fail_rfkill: > - free_page((unsigned long)bufferpage); > + free_page((unsigned long)buffer); > fail_buffer: > platform_device_del(platform_device); > fail_platform_device2: > -- > 1.7.9.5 > -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/